Noisy unit

[james]

Thanks for the update, Steve.

[stevegreenberg]

Using a separate power supply now and loving it. This unit is incredible, it's a whole new era of sound and control- WOW!!

thanks!

[james]

That's what we want to hear!

[xxsonussnz]

I'm powering the Wahoo via USB, my signal chain was: Bass -> Wahoo -> Zoom B3 - and wow the noise was unbearable!!

I actually thought I had a defective unit but I took it to rehearsal lastnight anyways thinking it might be something to do with the electronics in my lounge. At rehearsal, same problem! so I re-routed the signal chain as: Bass -> B3 -> Wahoo and boom no more noise! Unfortunately with this new routing I cannot use the DI out from the B3 which is a pain.

James, are you able to advise as to why this might be the case?

Cheers,
Kerry.

[james]

This is caused by ground loops, where the ground of the USB and the ground of the audio can be connected together externally. Some noise from the digital circuits in the Wahoo is on the ground path, and this usually goes back to the power supply so there is no noise on the audio. However, in some cases, with some USB power sources, it is easier for some current to pass through the audio ground than the power (USB) ground, so some of this noise appears on the audio.

The solution is to use a different USB power supply.

We have found that some USB power is not a problem because it is isolated from mains ground (Macs are usually pretty good, or any computer running from batteries, The Apple iPad/iPhone USB plug-in charger also works well).

If you are using USB not just for power, but also to remotely control the Wahoo, connecting a 9V DC supply will usually fix the problem because in this case the power comes from the 9V supply rather than USB.

You can also use ground isolators to fix this. There are a few USB isolators available (I have one here which I have tried and it works well). Or audio "hum isolators" which use transformers to remove ground loops.

I suspect the problem may be the DI output of the B3. Does it have a ground lift on it? Often DI outputs have this so that some resistance is added into the ground line to prevent these kind of ground loops.

[xxsonussnz]

Thanks for the reply James and the explanation - makes a bit more sense now.

Both the B3 and Wahoo are being supplied by the same USB power source ie. wall plug with two outputs. The B3 DI out was not used only the L Mono output.

Things I'm going to try: 1) seperate USB power supplies 2) B3 DI Out (which does have a ground lift switch)

I will let you know how it goes

[xxsonussnz]

Hi James,

I tried 1) seperate USB power supplies 2) B3 DI Out - and I'm afraid the noise is still unbearable with eiter and interestingly the ground lift using the DI Out made it even worse which really surprised me.

So I guess the only options left will be to try powering the Wahoo using either batteries or a 9vDC PSU - obviously not ideal but I'll give it a go anyways and report back.

Cheers,
Kerry.

[anabkemeir]

I too have had noise issues when the Wahoo was attached via usb to a laptop, when either the Wahoo was just connected to the laptop or when usb and power were connected to the wahoo. I tried a powered hub, but no help. It the laptop was running on battery and not plugged into wall outlet, there is no noise. I simply put a 3 prong ground lift adapter on the power supply of the laptop and no noise when the laptop is plugged in to power.......